I have seen Subsurface radius at higher values. I am currently using 3.67, 1.37, 0.68 with a Subsurface value of 0.01 which is considered a real-world value; I haven't seen any blue tinting around the mouth and have completely eliminated the self glowing issue many individuals are having. Consult the Poser manual and look at the PrincipledBsdf section. Also, there is a chart listing some known Subsurface radius values for different materials but I have found that those values are erroneous, they appear to be set in meters, not millimeters.